In recent years, a number of rotatable devices have been marketed, such as a fan or a bicycle wheel, which include flashing light emitting diodes (LEDs) to display a text message. These devices use the principle of “persistence of vision”. Persistence of vision (POV) refers to the phenomenon of the human vision in which an afterimage exists for a brief time (of the order of 10 ms to 40 ms). A POV display exploits this phenomenon by spinning a one-dimensional row of LEDs along a circular path at a sufficiently high frequency and controlling the flashing of the LEDs, so that a two-dimensional image is visible.
Wearable items, such as apparel and sports equipment, usually provide certain functionality to the user. For example, shoes, in particular sport shoes, generally provide friction between the foot and the ground, promote or facilitate certain aspects of the sport, and also protect the foot. Existing solutions provide shoes, apparel or garments with lights or image displaying devices to change the outer appearance or the shoe or enhance visibility of the shoe. Such devices or lights can display various graphical elements, for example, the logo of the manufacturer of the garment or of a certain sports team. Often provision of such displays affect or interfere with the primary functionality of the equipment or shoe.
Various light arrangements or image displaying devices for shoes are known. For example, U.S. Publication No. 2015/0029005A1 (entitled “Remotely Activated Illuminated Shoe”) discloses a show for which the illumination is controlled by a hand-held activation device, such as a keychain or smartphone, whereby a portion of the shoe is illuminated in a variety of burst modes.
Other examples are described in U.S. Pat. No. 8,474,146 B2, U.S. Pat. No. 8,769,836 B2, U.S. Pat. No. 9,226,542 B2 and U.S. Pat. No. 8,650,764 B2, which generally disclose articles of footwear with a color change portion capable of changing colors in response to a performance parameter, such as the distance travelled by the user.
U.S. Pat. No. 8,982,150 B2 describes a system for advertising on footwear by displaying promotional content on an electronic display of the footwear. The promotional content may be displayed in a manner that occupies 25% to 100% of the outer surface of the footwear. Additionally, the content can be displayed according to a plurality of conditions, including time of day, rate of motion of the footwear and environmental lighting condition around the footwear.
An article of footwear including an upper incorporating a knitted component having color-shifting properties is provided in U.S. Pat. No. 9,078,488 B 1. Color-shift properties are generated by one or more lenticular knit structures disposed across the upper of the article of footwear. The one or more lenticular knit structures generate a visual effect that changes the color of the article of footwear depending on the viewing angle.
U.S. Publication No. 2014/0268839A1 discloses an illumination device for apparel or other worn garments by a rider of a motorcycle or scooter for enhancing the recognition of the motorcycle's presence by proximate vehicles. The illumination device changes the illumination of the apparel or garment in response to changes in other light sources or the proximity of a vehicle.
U.S. Pat. No. 8,516,724 B2; U.S. Pat. No. 9,216,552 B2; and U.S. Publication No. 2016/0089816A1 generally disclose devices for displaying an image on apparel, for example, a shoe, which uses raised and recessed portions in a display layer to vary light transmission and generate the image.
Other solutions include U.S. Pat. No. 9,301,573 B2, which discloses a detachable electronic display that can be used to display of images, animations or videos on footwear on footwear; and WO 2016/040965A1, which describes light emitting diodes (LED) lights embedded in the sole of footwear. The LED lights are adapted, such that the intensity and color can be changed by the user with a standard short-range wireless interconnection, such as Bluetooth technology.
However, a common disadvantage of the above-described existing solutions is that they either provide one or more static images, are not suitable to provide information to a spectator as they are typically too small or are quite voluminous (e.g., making them heavy), and thus, may reduce the performance of the wearer or the functionality of the equipment. Using existing solutions, it is therefore currently impossible to have, for example, a shoe of a professional soccer player presenting information or a design element in response to a measurement or an event in such a way that they can be visibly recognized by spectators in a stadium or in front of a TV without impairing performance.